body{
	padding: 0;
	margin:0;
}
img{
	width: 100%;
}
article{
	width: 90%;
	margin:20px auto;
}
section{
	
}
section p{
	font-size: 0.9em;
	line-height:20px;
}
.tip{
	color: gray;
	font-size: 0.8em;
	border-bottom: 1px solid gray;
	line-height:20px;
}
h2{
	font-family: '黑体';
	font-size: 1.8em;
}